1. Field of Invention
Aspects of the invention pertain to surgical instruments, more particularly to instruments used during minimally invasive surgery, and still more particularly to instruments used to perform tissue sealing and cutting.
2. Art
During a surgical procedure, certain tissues such as blood vessels are first sealed before they are cut (bisected). One way to do this is with clamps. At least two clamps are applied to the vessel, and then the vessel is cut between the clamps. Another way to seal tissue (e.g., intestines) is with a stapler. Surgical staplers typically apply at least two staple rows on either side of a line to be cut. Such staplers use single-use staple cartridges, and often a cutting blade is mounted in the cartridge. A more effective way than clamping or stapling to seal tissue is by using radio frequency (RF) energy. An illustrative instrument used for such RF sealing is the LigaSure™ Atlas™ instrument available from ValleyLab, a Covidien Ltd. division. A disadvantage of such tissue sealing instruments is their limited lifespan, because the sealing electrodes deteriorate quickly with use. Typically, an entire RF sealing instrument is disposed of after a single surgical operation.
During minimally invasive surgical procedures (e.g., laparoscopy, either manual or robotically assisted), a surgeon may be required to manipulate tissue with two or more grasping instruments, and then remove one grasping instrument to allow a sealing instrument to be inserted. And so a surgeon may need to remove a grasping instrument to insert a sealing instrument, and then remove the sealing instrument to insert a cutting instrument, thus further slowing the surgery.
Further, the surgeon often has no indication that an acceptable clamping pressure exists between the sealing instrument jaws. Surgeons using manual instruments typically learn to judge by feel when an acceptable clamping pressure is reached, but they rely on a successful post facto tissue sealing indication from an associated electro-surgical unit to know that they used an acceptable clamping pressure. In a telerobotic surgical system context, however, such a clamping pressure indication may not be available, and in a manual context, there is a risk that a surgeon has not achieved the correct clamping force.
Therefore, what is required is a cost effective surgical instrument that performs both tissue cutting and sealing. What is further required is an instrument capable of grasping and manipulating tissue in addition to tissue cutting and sealing. And in addition, it is desirable to provide closed loop feedback that indicates that an acceptable clamping pressure exists before the sealing procedure is initiated.